Whatch the 2 videos at http:// coinrelicdownunder.wordpress.com/2011/10/20etrac. He gives you his settings, I found it very interesting and compared to TTF mono tone. Usting multi tone you can hear all the trash which you ignore and the High pitch tone stands out instead of the same high tone in 2TF on each piece of trash. Its worth watching and I'm going to try it next time out when the snow melts.